Is Alien: Isolation’s Nostromo DLC worth buying?

These downloadable missions faithfully recreate two key scenes from Ridley Scott’s 1979 horror classic, but with a few subtle twists. The premise is that MOTHER, the Nostromo’s supercomputer, is simulating these events to determine the best way to defeat the alien, which has allowed The Creative Assembly to play with the story in a way that isn’t strictly canon.

The first, Crew Expendable, focuses on the crew’s attempts to trap the xenomorph in the ship’s airlock and blow it out into space. In the film it was captain Dallas who bravely volunteered to climb into the ventilation system with the beast, but here you can choose who does it: Dallas, Ripley, or Parker. Your choice doesn’t affect the game in any way—only dialogue—but it’s a cool idea.

The sedate opening sets the scene. You’re free to explore the Nostromo before you climb to the lower decks and begin the mission. The ship has been beautifully, painstakingly realised, and it’s like stepping onto the set of Scott’s film. The dining table where the infamous ‘birth’ scene took place, the dimly-lit bridge, and the blinking lights of the MOTHER computer are all superbly authentic—although, as I discovered in this feature I wrote, not everything is 100% accurate.

Eventually you descend to the engineering deck and have to avoid the alien as you seal a series of vent covers scattered around the level. This is the least inspiring of the two missions in terms of level design, and you won’t find it particularly challenging if you’ve already finished the main game. It’s a notably smaller, more claustrophobic space than anywhere on Sevastopol, and you’ll need to make ample use of ducts and side-rooms to carefully manoeuvre around the creature.

The last sequence is better, replicating the film’s brilliant vent scene. You’re trapped in a dark metal maze with the alien, lit only by the burning tip of your flamethrower. Lambert monitors a motion tracker and shouts directions over the radio as you try to reach the exit. If you thought this moment was tense in the film, just wait until you’re in there with the creature yourself.

Last Survivor is the second, and best, of the DLC missions. It’s based on the last scenes of the film, in which Ripley attempts to engage the Nostromo’s self destruct and escape on a shuttle. In the film, Lambert’s death is left horribly ambiguous, but here you get to see the grisly aftermath of her and Parker’s last moments. Hunted by the alien, you must make your way through the belly of the ship and trigger the self-destruct as alarms wail and jets of steam suddenly burst from pipes.

This is a tough, tightly-designed mission—probably one of the best in the game—and does a great job of replicating the final, desperate moments of the film. You’re limited to basic supplies and a small amount of flamethrower fuel, forcing you to rely almost entirely on pure stealth, which is a nice contrast to the main game’s abundance of gadgets and weapons.

It’s clear these missions have been made especially for Alien fans. They’re a lovingly-crafted homage to the film, and they even managed to reunite most of the original cast including, crucially, Sigourney Weaver, who reprises her role as Ellen Ripley for the first time since the woeful Alien: Resurrection. Ash is voiced by a soundalike, but he really, really sounds like Ian Holm.

There’s a nice moment in an audio log that ties the DLC to Ripley's daughter Amanda's story in the main game, but otherwise they can be enjoyed as standalone experiences. The missions will cost you about £3/$4 each, which isn’t much considering how much love has been poured into them—although they aren’t that long, and you’ll be able to get through both of them in little over an hour. For an Alien fan, though, it’s a small price to pay to step inside a timeless science fiction classic.